9 Claims. (Cl. 154-42) This invention relates to the art of fastening together sheets or layers of material, especially flexible or yieldable materials such as fabric, paper, felt and other fibrous materials, metal foil and the like; in fact, any material that can be sewed.

The general object of the invention is to provide an improved method and apparatus for fastening two or more sheets of material together.

In accordance with the invention, two or more sheets or layers of material are fastened together by means of a stitching operation, the thread which is to hold the sheets together being formed during the stitching operation. The thread `is formed directly in the material. This is accomplished by introducing. a suitable synthetic fiber forming material into the sheet material by extrusion under appropriate pressure and temperature during the stitching operation.

A large number of synthetic fiber-forming materials suitable for carrying out my invention are available on the market under various trade names, vinyl resin, plastic, that used in making Vinylite being an example; or the material employed may be a nylon plastic, or a cellulose derivative plastic, that used in making rayon being an example. In addition, the synthetic fiber material employed may be a regenerated cellulose plastic. ployed may be a synthetic rubber compound, such for example as those used in making neoprene and'Lastron. It will be understood that the expression, synthetic fiber material, as used throughout this specification and the appended claims is intended to include any of the above and other similar compounds.

Some of these materials such as the Vinylite and nylon plastics, set upon extrusion, and require the introduction during the stitching operation of a single liquid only into the material to be secured together.

The remainder of the plastic compounds mentioned, such as the cellulose derivative plastics and the rubber compounds set upon being admixed with a suitable curing or coagulating or precipitating agent. Therefore, when these latter compounds are employed two liquids are introduced during the stitching operation into the sheet material to be secured together. It will be understood that the term liquid as here used, and as hereafter used, designates either the extruded material or the curing or coagulating agent, whether these materials are actually Also, the synthetic fiber material eml in the liquid state, or are in a plastic, or semiplastic, condition.

The apparatus for carrying out the method of the present invention may assume many different forms. In the accompanying drawings three embodiments of apparatus adaptable for the use of the compounds which require the introduction of two liquids and one embodiment suitable for introducing a single liquid have been illustrated. The invention will be better understood, particularly in its apparatus aspect, from a consideration of these drawings. In them:

Fig. 1 shows diagrammatically the preferred apparatus for stitching and simultaneously therewith introducing the liquids into the material;

Figs. 2, 3, 4 and 5 show successive steps in the operation of this apparatus;

Fig. 6 is a diagrammatic view similar to Fig. 1 showing a modification;

Figs. 7, 8 and 9 are views illustrating steps in the operation of the apparatus of Fig. 6;

Fig. 10 is a view similar to Fig. 1 of another modification;

Figs. 11 and 12 illustrate steps in the operation of the apparatus of Fig. 10;

Fig. 13 is a transverse section taken on line |3--I3 of Fig. 11;

Fig. 14 is a diagrammatic view also similar to Fig. 1 of another modification intended for employing a single liquid;

Figs. 15, 16, 17 and 18 are views illustrating steps in the operation of the apparatus of Fig. 14; and

Fig. 19 illustrates a modif-led form of needle.

Referring first to Figs. 1-12 inclusive, and particularly to Fig. 1, the two-liquid-apparatus includes a table I on which the superposed layers of material indicated by reference numeral 2 which are to be secured together rest. Associated with this table and coacting with the lowermost layer of' material 2 is a feed mechanism of any suitable type, such for example as a reciprocating feed bar 3 adapted to feed the material towards the left. Feed bar 3 may have the usual teeth although these are not shown since the drawings are diagrammatic.

Coacting with the upper surface of sheet material 2 is a presser foot 4 of the usual slotted type, and above the presser foot the apparatus is provided with a hollow needle 5 which projects downwardly from the lower part of a reservoir 6 which in turn is secured to the bottom of a reciprocating needle driving head I of any desired construction. It will be understood that needle 5, presser foot 4 and feed bar 3 are operated in timed relation by suitable mechanism (not shown) to cause the needle to be forced downwardly through the sheet material 2 and then upwardly, the material being fed forward during the upward stroke of the needle. Figs. 14 inclusive show various steps in one complete cycle, or downward and upward stroke, of the needle.

Hollow needle 5 is provided with a longitudinal interior passage 8 which is in communication with reservoir 6 at the top and with one or more discharge openings 9 adjacent the point of the needle. Reservoir 6 is in communication with a stationary tank IU through a flexible tubing Il. Tank I constitutes a source of supply of synthetic ber material under appropriate pressure so that as needle is forced downwardly through the sheet material 2 this synthetic material will be extruded from the opening or openings 9 and will be spread by the surface of the needle onto the edges of the holes formed in the several sheets 2 by the penetration of the needle.

The downward stroke of the needle terminates,

after its lower portion has been carried into a bath I2 of curing or coagulating liquid contained in a well I3 which is mounted in stationary position beneath table I. The needle is shown in Fig. 2 in this position. Appropriate heating means, (not shown) such as an electric heater and thermostat, are provided preferably in association with the reservoir 6 to maintain the synthetic material at the correct temperature.

On the upward stroke of the needle the mixture of synthetic material extruded from needle 5 and the curing bath liquid I2 is carried upwardly through the perforation passing through the several sheets of material 2, and the action of the curing bath on the synthetic material causes it to set immediately and form a through thread I4 extending from the bottom to the top of the superposed sheets 2.

The extrusion action and the movement of the needle in the perforation produce an enlargement I5 at the bottom of the lowermost sheet 2- and lateral extensions I6 of thread I4 between the several layers. The cured plastic material forming thread I4, with its integral bottom portion I5 and laterals I6 become bonded to the material of the sheets 2 and cause them to -be permanently secured to one another.

As the feed of the material'takes place preparatory to the next penetration of needle 5, the synthetic ber material extruded from needle 5 is carried along the upper surface of sheets 2 as indicated at I1. Also the ber material which is extruded from needle 5 while it was in the bath I2 on the previous down stroke provides a surplus which is indicated in Fig. 3 as an extension of thread I4 into the well I3. This surplus is carried along the lower surface of sheets n l 2 as indicated at I8 in Fig. 4.

The fiber material carried along from the end of needle 5 by the feed of the material as indicated by numeral I1 and the surplus fiber material I8 at the bottom form, on the next downward stroke of needle 5, complete top and botform a series of through threads I4 and top and bottom threads I 8 and 20, integrally connected with one another.

It is desirable to maintain the level of curing bath I2 adjacent the mouth of well I3, and this can be done by means of any suitable apparatus such for example as indicated in Fig. 1. Here the interior of well I3 is connected through a pipe 2| with level control tank 22. The curing liquid is admitted into tank 22 from a supply tank 23 by means of a valve 24 which is under the control of a float 25.

In the modification shown in Figs. 6-9 inclusive, the various parts are all as previously described in connection with Fig. 1 except the needle structure and supply for the two liquids. As here shown needle 5a is somewhat larger than needle 5 and is provided with two concentric liquid channels 25 and 26 in communication respectively with reservoirs 21 and 28,` one of which supplies the synthetic fiber material and the other of which supplies the curing liquid. The lower end of the needle is constructed in such a manner that the two liquids are mixed together in the throat 29 before being extruded through the tip 30 of the needle. A well I3a may be provided if desired to receive the surplus liquid mixture extruded from needle tip 30. The apparatus operates in a manner similar to that described previously, and as shown in Figs. '7, 8 and 9, to form a series of upright or through threads I4a connected by upper and lower threads I9a and 20a, the through threads being provided with laterals, such as IGa, as before. If the lower thread 20a is not required, well I3a may be omitted and the amount of liquid extruded from the needle tip reduced.

In the modification shown in Figs. 10-12 the reciprocating driving head 1 has a double needle structure attached to it.- Thus, hollow needles 3I and 32 are xed to their respective reservoirs 33 and 34 which in turn are secured to driving head 1. The synthetic fiber material is supplied to one of the reservoirs, for example, reservoir 33 through a flexible tubing 35, and the other liquid, for example the curing liquid is supplied to reservoir 34 through tubing 36.

The machine is provided with appropriate feed mechanism such as a reciprocating feed bar 31 which feeds the sheet material 2 Vtowards the left along the supports 38. The arrangement of the feed mechanism is such that at each stroke the sheet material 2 is fed forwardly by an amount corresponding to the spacing of needles 3l and 32. Thus, needle 3| which first penetrates the sheet material, forms an opening 39 therethrough and extrudes one of the liquids into the same. Then the sheet material 2 is fed toward the left and on the second down stroke of driving head 1, needle 32 passes through the same opening 39 and injects the second liquid, mixing it with the liquid previously introduced by needle 3|.

In this modification the well I3 in which the curing liquid is maintained at a predetermined level is omitted, and in its place feed bar 31 is provided with a lengthwise channel 40 which extends both between and beyond two spaced holes 4I and 42 which are provided to permit the passage of the lower ends of needles 3| and 32 respectively.

On the down stroke of needle 3|, as shown in Fig. 10, one of the liquids, for example the synthetic fiber material, is extruded through the openings 9a into the opening 39 formed by the penetration of this needle through the several layers of sheet material or work 2. needle continues its motion somewhat below the lowermost of these layers, some of the synthetic material is ejected from holes 9a into channel 40 adjacent hole 4I.

In Fig. 11 the needles have returned to their uppermost position and a forward stroke of feed bar 31 has taken place, carrying opening 39 beneath the second needle 32. Opening 39 has received the synthetic fiber material, and the synthetic material within channel 40 has been carried along the lower surface of the work 2. Also, a somewhat similar thread 43 of this material has been laid along the top of the work 2 in the space between the two toes of presser foot 4. On the next downward strokes of the needles, the curing liquid from needle 32 is mixed with the synthetic fiber previously deposited in opening 39.

In Fig. 12 such downward stroke followed by an upward stroke of the needle has occurred and a second feeding stroke of feed bar 31 has also taken place. This feeding stroke has caused the curing liquid from needle 32 to be mixed with the synthetic fiber material previously deposited along the lower surface of sheet material 2 in channel 40 and extending between opening 39 formed on the rst downward stroke of needle 3| and opening 44 which has been formed on the second downward stroke of needle 3|. Curing material 45 from needle 32 is also laid onto the synthetic ber material 43 on the top of sheet material 2. The two liquids having thus been brought together, the setting or curing reaction takes place forming a vertical or through thread 45 and the bottom and top threads 41 and 48 respectively. Continued operation of the mechanism forms a succession of through threads 46 interconnected by the top and bottom threads.-

This modification also illustrates a modified form of needle in which the extruding apertures 9a are arranged in a plurality of rows. These are shown to better advantage in Fig. 13. A filament of the synthetic ber material is extruded from each of these apertures and these filaments join one another to form the through threads 46 after the addition of the curing liquid. Referring now to Figs. 14-18 inclusive, a stitching mechanism which is adapted to employ a single liquid is here illustrated. As before, the several superposed sheets of material or work 2 rest upon a support 49 which may be similar to either of supports or 38, or have any other convenient form. Also, a reciprocating feed bar 31a, or other appropriate feeding device, is provided, which has a channel 49a in its upper surface and a passageway 4|a for the single needle 5. It will be understood, however, that a needle with additional extrusion openings similar to needles 3|, 32 may be used if desired. Also the mechanism includes the usual presser foot 4.

In this mechanism needle is given a rotary motion simultaneous with its vertical reciprocating motion, for the purpose of twisting the several filaments of synthetic material extruded from the apertures 9 into a single thread structure. For this reason the reservoir 6 to which needle 5 is attached is secured to a simultaneously reciprocating and rotating head 50. Head 50 is supported between the lower end of a vertically reciprocating hollow bar 5| having at As the its upper portion a cross head 52 which is engaged by a crank 53 to impart the reciprocating motion to it.

A flexible tubing 54 supplies the synthetic fiber material from a pressure supply tank 55 to the interior of hollow reciprocating bar 5|. The lower end of hollow bar 5| is connected to head to impart reciprocating movement thereto; this connection includes a packing gland 56 to allow rotation of head 50.

In order to impart the rotating movement to head 50, it is supported within a rotating ring or collar 51, and interconnected therewith by vertical slideways or splines 58 so that rotation of collar 51 is imparted to head 5|) without interferring with the reciprocating movement of the head. Collar 51 is supported in a suitable bearing indicated by numeral 59 on a stationary frame 65. Sleeve 51 is rotatably driven by a vertical shaft 6|, the lower end' of which has a pinion 62 which meshes with gear teeth 63 on the upper end of the sleeve.

This apparatus being a single liquid apparatus, a synthetic organic plastic material such as Vinylite or nylon is employed as the synthetic fiber material and is supplied to the needle 5 from the supply tank through the connections described above. As shown in Fig. 15 needle 5 has made a downward stroke through the work 2, the rotation of needle 5 serving to Wipe the plastic material onto the surfaces of the opening through the sheets formed by the penetration of the needle. At the lower end of the stroke a predetermined amount of this material is deposited in channel 40a in feed bar 31a.

On the upward stroke, as shown in Fig. 16, the several filaments or bers of the plastic which are extruded from the several apertures 9 are twisted into a single through thread 64 extending from the plastic material 65 in channel 40a to the topof the work 2. It will be understood that the plastic is extruded under the appropriate conditions of temperature and pressure to cause it to set properly, and that this setting takes place substantially instantaneously upon extrusion, leaving the through thread 65 completely formed and serving to secure together the several sheets of material 2. The attachment of the sheets to one another is also enhanced by the flowing of the plastic material into the interstices between the several sheets to form the lateral extension |6a of this thread.

In Fig. 17 a feeding operation is taking place carrying the work forward to a position where it is ready for the next downward stroke of needle 5. The rotation of the needle continuing, the plastic which has been extruded during this feeding movement is formed into a twisted mass 66, which in Fig. 8 has been laid on top of the Work 2 to form the upper thread. The material 65 which was deposited in channel 40a has been drawn out along,r the bottom surface of the work 2 in this channel to form the lower thread 61.

In the above described mechanism for forming a synthetic thread during the stitching operation employing a single liquid, while it is preferable to rotate the needle so as to twist the plurality of filaments into a single strand, this is not necessary to the successful operation of the method and apparatus of the invention, and accordingly, apparatus employing a needle which reciprocates without rotating may be used if desired.

In Fig. 19 there has been illustrated a modiiled form of needle in which the synthetic ber material is conducted along a groove in the surface of the needle instead of being carried through a duct within the needle. In this modification the needle is indicated by reference numeral 68 and is provided with a surface groove 69 extending longitudinally of the needle to the top of the point portion 10. Here groove 69 connects with a downwardly sloping passage 1l which extends through point to the opposite side thereof and terminates preferably along the sloping surface of the point.

Needle 68 reciprocates in a bore which is formed in a body 13, the lower surface of which is held in contact with the work 2 and may constitute the presser foot of the mechanism. The upper end of bore 12 communicates with a reservoir 'H which may have the form of a cylinder which is closed at its upper end by means of a piston 15 which reciprocates with needle 68.

The synthetic ber material is supplied to reservoir 14 through a connecting tubing 16 under appropriate pressure. The bore 12 connes the liquid within groove 69 and thereby conveys the liquid to the surface of the work 2. As the needle continues to penetrate the work, the walls of the opening formed in it by the needle serve to confine the plastic and cause it to flow along the groove and into the sloping passage 1I, or to be discharged against the walls of the opening in the work.

It will be understood that with any of the various modifications of the improved stitching apparatus above described, heating or cooling means (both if desired) may be associated with the mechanism in order to maintain the required temperature conditions for the proper setting of the particular synthetic ber material employed.

While a number of modifications of the apparatus have been described, it will be understood that these are all of a diagrammatic nature, and that numerous changes may be made in such apparatus and in the details of carrying out the method of the present invention without departing from the spirit of this invention or exceeding its scope which is intended to be set forth in the appended claims.

In these claims it will be understood that the term thread is used to include either a thread carried through from one surface to the other of the Work, or a thread both extending through and carried along one or both surfaces of the work.

The thread in the holes through the work adheres to the walls of the holes, and by thus forming an adhesive ller for the holes strengthens the seam which otherwise would be weakened by the presence of the holes. This is a factor of importance in the closing of such articles as paper shipping sacks.

I claim:

l. In a machine for stitching sheets of material together, a work support, a needle mounted to reciprocate with respect to said support, means for reciprocating said needle, said needle having an extrusion aperture adjacent its point, and means for supplying a liquid thread-forming material to said needle for extrusion from said aperture during the stitching operation.

2. In a machine for stitching sheets of material together, a work support, a hollow needle mounted to reciprocate with respect to said support, means for reciprocating said needle, said needle having an extrusion aperture adjacent its point, and means for supplying a thread-forming liquid material under pressure to the upper end of said needle to cause said material to be extruded from said aperture during the stitching operation.

3. In a machine for stitching sheets of material together, a work support, a needle mounted to reciprocate with respect to said support, and means for simultaneously reciprocating and rotating said needle, said needle having a plurality of extrusion apertures adjacent its point,

' and means for supplying a liquid thread-form-- ing material to said needle for extrusion from said apertures during the stitching operation.

4. In a machine for stitching sheets of material together, a work support, a needle mounted to reciprocate with respect to said support, means for reciprocating said needle, said needle having an extrusion aperture adjacent its point, means for supplying a liquid thread-forming material to said needle for extrusion from said aperture during the up stroke as well as the down stroke of said needle, said needle depositing said threadforming liquid in the openings in the work made by the needle to form threads extending through the work, and means for feeding work on said support to cause the thread-forming liquid to be applied to the top surface of the work between said through threads.

5. In a machine for stitching sheets of material together, a work support, a liquid receptacle below said support, a needle mounted to reciprocate with respect to said support, means for reciprocating said needle and causing the lower end of the needle to enter said receptacle, said needle having an extrusion aperture adjacent its point, and means for supplying a liquid threadforming material to said needle for extrusion from said aperture during the stitching operation, said needle depositing said thread-forming liquid in said liquid receptacle and in the openings in said sheet material made by the penetration of the needle, means for feeding the work and simultaneously causing said thread-forming liquid to be carried along both the lower and upper surfaces of said work thereby forming lower and upper threads lioined together by the threads formed in said openings.

6. In a machine for stitching sheets of matcrial together, a work support, a liquid reservoir for curing liquid below said support, a needle mounted to reciprocate with respect to said support, means for reciprocating said needle and causing the lower end of the needle to enter said reservoir, said needle having an extrusion aperture adjacent its point, and means for supplyin;f a liquid threadforming material to said needle for extrusion from said aperture during the stitching operation, said needle depositing said thread-forming liquid and curing liquid from said reservoir in the openings in said sheet material made by the penetration of the needle, means for feeding the work and simultaneously causing said liquids to be carried along both the lower and upper surfaces of said work thereby forming lower and upper threads joined together by the threads formed in said openings.

'7. In a machine for stitching sheets of material together, a work support, a needle mounted to reciprocate with respect to said support, means for reciprocating said needle, said needle having an extrusion aperture adjacent its point, a mixing chamber adjacent said aperture. a pair of ducts extending lengthwise of said needle and connected to said mixing chamber, and means for supplying a liquid thread-forming material 9 to one of said needle ducts, and a curing liquid to the other of said ducts.

8. In a machine for stitching sheets of material together, a work support, a pair of spaced needles mounted to reciprocate together with respect to said support, means for reciprocating said needles, said needles each having an extrusion aperture adjacent its point, means for supplying a liquid' thread-forming material to one of said needles for extrusion from its aperture during the stitching operation, means for supplying a curing liquid to the other of said needles for extrusion therefrom, said needles depositing said thread-forming liquid and said curing liquid simultaneously in spaced openings in said sheet material, and means for feeding work on said support a distance corresponding to the spacing of said needles thereby causing the second needle to enter the opening made by the rst needle on the previous stroke and causing mixing of said liquids to produce threads in said openings.

9. In a machine for stitching sheets of material together, a work support, a work feeding bar, a liquid receiving channel below said support in said bar, a pair of spaced needles mounted to reciprocate with respect to said support, means for simultaneously reciprocating said needles and causing the lower ends of the needles to enter said channel, said needles each having an extrusion aperture adJacent its point,meansfor supplying a liquid thread-forming material to one of said needles for extrusion from said aper-y ture during the stitching operation, means for supplying a curing liquid to the other o1 said needles for extrusion therefrom, means for feeding said work a distance corresponding to the spacing of said needles thereby causing said needles successively to deposit said liquids in each opening made in the work, liquids being carried along both the lower and upper surfaces of said work thereby forming lower and upper threads joined together by threads in said openings.

CARL E. LINCOLN.

REFERENCES CITED The following references are of record in the file of this patent: